Fundamental investigation and application of high-speed VCB for DC power system of railway

The fundamental phenomena of the high-speed vacuum circuit breaker, which forced the fault current to zero, for the DC power system were investigated by the experiments. The interruption characteristics of the circuit breaker, which was consisted from a vacuum interrupter, a high frequency current source and a high-speed driving mechanism, were estimated experimentally. The arcing period of the high-speed vacuum circuit breaker is much shorter than that of conventional circuit breaker. The arc behavior of the test electrodes immediately after the electrode separation was observed by a high-speed video camera. The relation between the current waveform just before current zero and the interruption ability by varying the high frequency current source was investigated. The results demonstrate the interruption characteristics and the arc behaviors of the high-speed vacuum circuit breaker. And the high-speed vacuum circuit breakers were applied for DC1500V and DC750V power systems of railway.